Recipe theorem for the Tutte polynomial for matroids, renormalization group-like approach

Using a quantum field theory renormalization group-like differential equation, we give a new proof of the recipe theorem for the Tutte polynomial for matroids. The solution of such an equation is in fact given by some appropriate characters of the Hopf algebra of isomorphic classes of matroids, characters which are then related to the Tutte polynomial for matroids. This Hopf algebraic approach also allows to prove, in a new way, a matroid Tutte polynomial convolution formula appearing in W. Kook {\it et. al., J. Comb. Series} {\bf B 76} (1999).Comment: 14 pages, 3 figure

Current understandings of sex-based harassment and stalking perpetration

Sex-based harassment and stalking are highly prevalent forms of interpersonal aggression that often result in an array of detrimental and severe impacts for victims. In this chapter, we examine some of the common challenges associated with defining and legislating against sex-based harassment and stalking, as well as considering existing classifications of behaviour and perpetrator motivations. In doing so, our aim is to highlight the complex nature of these forms of interpersonal aggression and the difficulties associated with ascertaining boundaries between ‘reasonable’ and ‘unreasonable’ behaviour. We proceed to discuss the importance of appropriately targeted evidence-based educational campaigns to increase public awareness and understanding regarding the reality of sex-based harassment and stalking. Our conclusion is that increased education will enable greater recognition of the diverse behaviours that constitute sex-based harassment and stalking, so that people are better able to identify both their own and others’ victimisation experiences

Superluminous supernovae: No threat from Eta Carinae

Recently Supernova 2006gy was noted as the most luminous ever recorded, with a total radiated energy of ~10^44 Joules. It was proposed that the progenitor may have been a massive evolved star similar to eta Carinae, which resides in our own galaxy at a distance of about 2.3 kpc. eta Carinae appears ready to detonate. Although it is too distant to pose a serious threat as a normal supernova, and given its rotation axis is unlikely to produce a Gamma-Ray Burst oriented toward the Earth, eta Carinae is about 30,000 times nearer than 2006gy, and we re-evaluate it as a potential superluminous supernova. We find that given the large ratio of emission in the optical to the X-ray, atmospheric effects are negligible. Ionization of the atmosphere and concomitant ozone depletion are unlikely to be important. Any cosmic ray effects should be spread out over ~10^4 y, and similarly unlikely to produce any serious perturbation to the biosphere. We also discuss a new possible effect of supernovae, endocrine disruption induced by blue light near the peak of the optical spectrum. This is a possibility for nearby supernovae at distances too large to be considered "dangerous" for other reasons. However, due to reddening and extinction by the interstellar medium, eta Carinae is unlikely to trigger such effects to any significant degree.Comment: 19 pages, 2 figures; Revised version as accepted for publication in Astrobiolog

Lipoxygenase and cyclooxygenase metabolism: new insights in treatment and chemoprevention of pancreatic cancer

The essential fatty acids, linoleic acid and arachidonic acid play an important role in pancreatic cancer development and progression. These fatty acids are metabolized to eicosanoids by cyclooxygenases and lipoxygenases. Abnormal expression and activities of both cyclooxygenases and lipoxygenases have been reported in pancreatic cancer. In this article, we aim to provide a brief summary of (1) our understanding of the roles of these enzymes in pancreatic cancer tumorigenesis and progression; and (2) the potential of using cyclooxygenase and lipoxygenase inhibitors for pancreatic cancer treatment and prevention

Interview with Adrian Raftery

Professor Adrian E. Raftery is the Boeing International Professor of Statistics and Sociology, and an adjunct professor of Atmospheric Sciences, at the University of Washington in Seattle. He was born in Dublin, Ireland, and obtained a B.A. in Mathematics and an M.Sc. in Statistics and Operations Research at Trinity College Dublin. He obtained a doctorate in mathematical statistics from the Universit\'e Pierre et Marie Curie under the supervision of Paul Deheuvels. He was a lecturer in statistics at Trinity College Dublin, and then an associate and full professor of statistics and sociology at the University of Washington. He was the founding Director of the Center for Statistics and Social Sciences. Professor Raftery has published over 200 articles in peer-reviewed statistical, sociological and other journals. His research focuses on Bayesian model selection and Bayesian model averaging, model-based clustering, inference for deterministic models, and the development of new statistical methods for demography, sociology, and the environmental and health sciences. He is a member of the United States National Academy of Sciences, a Fellow of the American Academy of Arts and Sciences, an Honorary Member of the Royal Irish Academy, a member of the Washington State Academy of Sciences, a Fellow of the American Statistical Association, a Fellow of the Institute of Mathematical Statistics, and an elected Member of the Sociological Research Association. He has won multiple awards for his research. He was Coordinating and Applications Editor of the Journal of the American Statistical Association and Editor of Sociological Methodology. He was identified as the world's most cited researcher in mathematics for the period 1995-2005. Thirty-three students have obtained Ph.D.'s working under Raftery's supervision, of whom 21 hold or have held tenure-track university faculty positions.Comment: 17 pages, 8 figure

The Role of PPARγ Receptors and Leukotriene B4 Receptors in Mediating the Effects of LY293111 in Pancreatic Cancer

Pancreatic cancer is a devastating disease in which current therapies are inadequate. Separate lines of research have identified the 5-lipoxygenase/leukotriene B4 receptor pathway and the PPARγ pathway as potential targets for prevention or treatment of this disease. LY293111 was originally designed as a potent leukotriene B4 receptor antagonist for treatment of inflammatory conditions. LY293111 was also known to have inhibitory effects on 5-lipoxygenase, which is upstream of the production of leukotrienes. LY293111 was shown to have potent anticancer effects in pancreatic cancer and several other solid malignancies, where it caused cell cycle arrest and marked apoptosis. Subsequently, it came to light that LY293111 exhibited PPARγ agonist activity in addition to its effects on the 5-lipoxygenase pathway. This raises the question of which of the two targets is of greatest importance with regard to the anticancer effects of this agent. The evidence to date is not conclusive, but suggests that the effects of LY293111 may be mediated by both LTB4 receptors and PPARγ

Intestinal invasion and disseminated disease associated with Penicillium chrysogenum

BACKGROUND: Penicillium sp., other than P. marneffei, is an unusual cause of invasive disease. These organisms are often identified in immunosuppressed patients, either due to human immunodeficiency virus or from immunosuppressant medications post-transplantation. They are a rarely identified cause of infection in immunocompetent hosts. CASE PRESENTATION: A 51 year old African-American female presented with an acute abdomen and underwent an exploratory laparotomy which revealed an incarcerated peristomal hernia. Her postoperative course was complicated by severe sepsis syndrome with respiratory failure, hypotension, leukocytosis, and DIC. On postoperative day 9 she was found to have an anastamotic breakdown. Pathology from the second surgery showed transmural ischemic necrosis with angioinvasion of a fungal organism. Fungal blood cultures were positive for Penicillium chrysogenum and the patient completed a 6 week course of amphotericin B lipid complex, followed by an extended course oral intraconazole. She was discharged to a nursing home without evidence of recurrent infection. DISCUSSION: Penicillium chrysogenum is a rare cause of infection in immunocompetent patients. Diagnosis can be difficult, but Penicillium sp. grows rapidly on routine fungal cultures. Prognosis remains very poor, but aggressive treatment is essential, including surgical debridement and the removal of foci of infection along with the use of amphotericin B. The clinical utility of newer antifungal agents remains to be determined

Frondoside A suppressive effects on lung cancer survival, tumor growth, angiogenesis, invasion, and metastasis

A major challenge for oncologists and pharmacologists is to develop less toxic drugs that will improve the survival of lung cancer patients. Frondoside A is a triterpenoid glycoside isolated from the sea cucumber, Cucumaria frondosa and was shown to be a highly safe compound. We investigated the impact of Frondoside A on survival, migration and invasion in vitro, and on tumor growth, metastasis and angiogenesis in vivo alone and in combination with cisplatin. Frondoside A caused concentration-dependent reduction in viability of LNM35, A549, NCI-H460-Luc2, MDA-MB-435, MCF-7, and HepG2 over 24 hours through a caspase 3/7-dependent cell death pathway. The IC50 concentrations (producing half-maximal inhibition) at 24 h were between 1.7 and 2.5 mu M of Frondoside A. In addition, Frondoside A induced a time- and concentration-dependent inhibition of cell migration, invasion and angiogenesis in vitro. Frondoside A (0.01 and 1 mg/kg/day i.p. for 25 days) significantly decreased the growth, the angiogenesis and lymph node metastasis of LNM35 tumor xenografts in athymic mice, without obvious toxic side-effects. Frondoside A (0.1-0.5 mu M) also significantly prevented basal and bFGF induced angiogenesis in the CAM angiogenesis assay. Moreover, Frondoside A enhanced the inhibition of lung tumor growth induced by the chemotherapeutic agent cisplatin. These findings identify Frondoside A as a promising novel therapeutic agent for lung cancer

Disease gravity and urgency of need as guidelines for liver allocation

One thousand one hundred and twenty-eight candidates for liver transplantation were stratified into five urgency-of-need categories by the United Network for Organ Sharing (UNOS) criteria. Most patients of low-risk UNOS 1 status remained alive after 1 yr without transplantation; the mortality while waiting was 3% after a median of 229.5 days. In contrast, only 3% of those entered at the highest risk UNOS 5 category survived without transplantation; 28% died while waiting, the deaths occurring at a median of 5.5 days. The UNOS categories in between showed the expected gradations, in which at each higher level fewer patients remained as candidates throughout the 1-yr duration of study while progressively more died at earlier and earlier times while waiting for an organ. In a separate study of posttransplantation survival during the same time period, the best postoperative results were in the lowest-risk UNOS 1 and 2 patients (88% combined), and the worst results were those in UNOS 5 (71%). However, a relative risk cross-analysis showed that a negative benefit of transplantation may have been the result in terms of 1-yr survival for the low-risk elective patients, but that a gain in life extension was achieved in the potentially lethal UNOS categories 3, 4 and 5 (greatest for UNOS 3). These findings and conclusions are discussed in terms of total care of patients with liver disease, and in the context of organ allocation policies of the United States and Europe